Try this, I use this in External Images for RDLC.
Just initialize the image parameter like a normal string parameter, and set the
Me.ReportViewer1.LocalReport.EnableExternalImages
to
TRUE
Dim ImgParam As New ReportParameter("ImgParam", "")
Dim path = _
System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)
ImgParam = New ReportParameter("ImgParam", path & "\myImg.png", True)
Dim parameters As ReportParameter() = {ImgParam}
ReportViewer1.Reset()
With Me.ReportViewer1.LocalReport
.EnableExternalImages = True
.SetParameters(parameters)
End With
Me.ReportViewer1.RefreshReport()